Some children are set to go back to primary schools in England, but big questions remain about their role in the pandemic.
Children can catch coronavirus and sometimes – thankfully rarely – become seriously ill.
But it is unclear how much they might be spreading it to each other and to adults, including staff.
Here is what experts understand so far about young people and coronavirus.
Do children get sick?
It remains the case that, overall, older people are most at risk of complications from the virus.
The average age of people being admitted to critical care units in England, Wales and Northern Ireland was 60 as of 24 April, an audit by a research charity suggested.
“Children have so far accounted for between 1% and 5% of diagnosed Covid-19 cases, have often milder disease than adults and deaths have been extremely rare,” according to Prof Adilia Warris, a paediatric infectious diseases specialist at the University of Exeter.
Are children spreaders or “superspreaders”?
Young children are superspreaders of other diseases, such as flu. Children are considered a high risk group when it comes to flu, but so far appear to be at low risk of becoming very ill from coronavirus.
One of the missing pieces of the puzzle is how much children carry coronavirus and spread the disease to others, even if they don’t often become ill themselves.
It is too soon to know how infectious people of any age with no symptoms, or only very mild ones, are to others.
Coronavirus is transmitted in a similar way to the flu virus – through coughing or touching contaminated objects, such as pens and door handles.
Keeping 2m (6ft) away from other people at all times and washing your hands before touching your face or eating food helps stop the spread of coronavirus. But these preventive measures are challenging even for adults to maintain.
Whether children are spreaders or not remains “one of the many unknowns with the current coronavirus outbreak”, says Prof Matthew Snape from the University of Oxford. He is beginning research into how many children and teenagers have been infected and developed immunity.
“Understanding this is vital to understanding how to manage the outbreak response, including decisions about when to re-open schools,” he says.
Why send young children back to school first?
Government guidelines say they are starting with Reception, Year 1 and Year 6 children because:
these year groups have important educational needs
younger children are less likely to become unwell if infected
older children are more likely to have higher numbers of contacts outside school so pose a greater transmission risk
older children are typically better able to learn at home
Should children wear masks at school?
While face coverings may help reduce the chance of spreading the disease when social distancing rules are difficult to follow, the government is not recommending their use in UK schools.
Guidance explains that young children may find it difficult to use them without assistance and that focus should be on washing hands and other good hygiene measures.
Are children immune?
One theory for why children generally have no or milder symptoms is that their lungs might contain fewer of the receptors that coronavirus uses to infect cells. But experts say there is no good evidence to support this.
And there have been reports of a very small number of children with coronavirus getting very sick and developing an overactive inflammatory immune response.
What about Kawasaki-like disease?
An urgent alert was issued to GPs after several children presented with symptoms similar to Kawasaki disease – a potentially fatal syndrome that affects blood vessels – including a high temperature, low blood pressure, a rash and difficulty breathing.
The syndrome appeared to be similar to the over-active immune response, known as a “cytokine storm”, seen in some adults with Covid-19. In many cases, it seems it is the body’s immune response rather than the virus itself that proves life-threatening.
But these symptoms identified in children are rare events – known to affect about 20 children so far – and not all of them tested positive for Covid-19.
Prof Rosalind Smyth, a consultant in paediatric respiratory medicine at Great Ormond Street Hospital, points out: “Our understanding of this condition in children is limited.
“We should investigate fully these children, with Sars-CoV-2, who present with a multi-system inflammatory disease to assess whether this is a presentation of Covid-19,” she says.
When to seek help
While children can catch coronavirus, it is rarely serious. If your child is unwell it is likely to be a non-coronavirus illness, rather than coronavirus itself.
The Royal College of Paediatrics and Child Health advises parents seek urgent help (call 999 or go to A&E) if their child is:
Becoming pale, mottled and feeling abnormally cold to the touch
Has pauses in their breathing (apnoeas), has an irregular breathing pattern or starts grunting
Has severe difficulty in breathing becoming agitated or unresponsive
Is going blue around the lips
Has a fit/seizure
Becomes extremely distressed (crying inconsolably despite distraction), confused, very lethargic (difficult to wake) or unresponsive
Develops a rash that does not disappear with pressure (the ‘glass test’)
Has testicular pain, especially in teenage boys
What about pre-existing conditions?
Underlying health conditions also play a role, regardless of age.
For example, there are about five-and-a-half million people in the UK of all ages who have asthma – and this puts you at higher risk of severe illness if you contract coronavirus.
Children with existing health conditions that put them at much higher risk of complications from coronavirus are being advised to stay at home – a protective precaution called shielding.